Full-waveform inversion (FWI) is a method that may be used to build, for example, a high resolution seismic velocity model from the nonlinear, iterative minimization of the misfit between observed and synthetic data. The task of accurately recovering the geometry of salt bodies, typically found in geologically complex marine environments like the Gulf of Mexico, presents a great challenge to FWI for many reasons, one of which being the lack of low frequencies in the data. Therefore, the salt geometry often must be manually picked by seismic interpreters, which is not only subjective but is also a time-consuming and costly process. It also has proved difficult to invert density using traditional FWI when using, for example, the Gardner approximation at a subsurface boundary. Better definition of the salt geometry has been shown to improve imaging in the subsalt sedimentary regions.